The next launch of a new crew for the International Space Station will be delayed by more than a month due to problems that were discovered with the Russian-built spacecraft, the head of Russia's Federal Space Agency confirmed today (Jan. 31).

The Soyuz TMA-04M was scheduled to launch to the space station on March 29, but issues with the spacecraft's descent vehicle were uncovered during tests last week. But that flight will now be pushed back by about 45 days, according to Russian news reports.

"Now, the management of Energia corporation is drafting a new plan, under which the launch will be delayed for a month, [until] late April," Vladimir Popovkin, chief of the Russian Federal Space Agency, told the Russian ITAR-TASS news service.

According to Popovkin, the delay is in response to problems with the Soyuz TMA-04M re-entry capsule, which failed a test to ensure that it was hermetically sealed.

A new targeted launch date will be set after a teleconference with NASA on Thursday (Feb. 2), reported Ria Novosti.

"We're sorting it out, we'll be through later this week," Popovkin said.

The Soyuz spacecraft is slated to launch NASA astronaut Joe Acaba and Russian cosmonauts Gennady Padalka and Sergei Revin to the space station to replace an outgoing crew.

The space station is currently home to six astronauts; three Russians, two Americans and one Dutch spaceflyer. Commander Dan Burbank, of NASA, and Russian cosmonauts Anton Shkaplerov and Anatoly Ivanishin are scheduled to return to Earth on March 16.

"There is plenty of margin for the current space station crew to stay onboard longer, if necessary, and plenty of margin in the manifest for upcoming launches," Clem told SPACE.com last week.